The present invention relates to an electrical connector system having an arrangement for connecting a wire conductor to a metal contact and, more particularly, to a metal contact having an open barrel portion which receives a wire conductor therein and is closed on the wire by multiple opposed indents arranged at an angle to the longitudinal axis of the contact.
It is well known in the prior art to provide an electrical contact having an open barrel portion with indents which close the barrel and thus secure the contact to the wire conductor inserted therein. Various types of indents have been utilized, including full circumferential indents, a single indent, opposed indents, multiple indents and multiple, angled indents. An example of a full circumferential indent is shown in U.S. Pat. No. 2,929,864 by Aune et al, while an example of a single indent is shown in U.S. Pat. No. 2,429,585 by Rogoff. An example of multiple, angled indents is shown in U.S. Pat. No. 2,816,276 by Fuller et al.
A full circumferential indent is difficult to accomplish and results in a general oval cross section rather than a circle. Through this arrangement there is little keying or centering of the wire conductor in the contact. A single indent requires a very deep indentation to secure the contact to the wire conductor which causes gross distortion of the contact cross section. Opposed indents permit the use of a medium-depth indentation but again cause distortion to the contact. Multiple opposed indents have been proposed as the most desirable way to provide medium-depth and minimum distortion of the contact while attaching that contact to a wire conductor. Angled, multiple opposed indents have the same advantage as multiple indents but each still tend to distort the contact, especially when the indents are formed with vertical walls surrounding the indent on all sides.
In the prior art, multiple opposed indents are generally parallel to the axis of the contact and work satisfactorily on a contact manufactured by a screw machine from a solid piece of metal. However, these mutiple opposed indents do not work satisfactorily with a contact manufactured by a continuous die stamping machine from a rolled or stamped piece of sheet metal. The reason for this is that a rolled or stamped sheet metal contact must, due to its construction, be provided with a seam which runs through the outer surface of the contact parallel to its longitudinal axis. When the open barrel portion of a sheet metal contact is closed by a multiple opposed crimping arrangement, there is a high probability that one of the multiple opposed indents will hit or come close enough to the seam so as to open or separate the seam and deform the contact beyond an allowable tolerance. The angled, multiple opposed indents of the prior art were developed to solve this problem. However, such indents continue to distort a sheet metal contact.